On Monday, the U.S. Supreme Court will take up a case that will have a lasting effect on American laws and virtually every American's access to health care. For three days, the justices will hear arguments regarding the constitutionality of the Affordable Care Act - a medical insurance overhaul that the U.S. Congress passed two years ago.

Three families explain what's at stake for them.

Just like he did four years ago, Miles Fawcett is there to catch his daughter when she needs him.

Serena was born with a severe liver defect. Her dad donated part of his liver to save his little girl's life. Now both have what's called a pre-exisiting condition.

Key aspects and programs of the Affordable Care Act:

Adult children can remain on their parent’s insurance coverage through the age of 26.

An end to lifetime limits on the dollar value of benefits available to people with serious medical conditions.

Business with more than 200 employees must enroll their employees in health insurance programs or pay a penalty.

Businesses with 50 to 200 employees who work 30 hours or more a week must offer insurance or money to workers who want to get insurance elsewhere.

Businesses with less than 50 employees are exempt from coverage provisions.

The Affordable Health Care law says no insurance company can deny coverage based on that. Serena's mother, Mira, worries what might happen if the Supreme Court rules the law unconstitutional.

“It’s difficult for me to think about somebody who’s gone through something through no fault of their own, who’s had to go through so much, to have the bottom drop out like that," she said.

Steve Fleishman runs a bagel business and does not offer health care to every employee. He would see no change if he stays under 50 employees. But, if he hires more, Fleishman would have to offer affordable coverage to his regular workers or pay a penalty.

He says - in this economy - there's not much profit left over when he wraps up the day, so, he'd have to raise prices and cut staff.

“I’d want to fall into the category of somewhere between 40 and 49 employees, so somewhere along the line we’d have to trim down and work a little harder to not be in that category so we wouldn’t have to pay for health benefits," said Fleishman.

Dianna Buckett is studying for an advanced degree in public health at Johns Hopkins University. The new law allows her to remain under her parents' health insurance until age 26, even after graduation.

“There’s not a lot out there that’s a full-time position without prior job experience," said Buckett. "A lot of what I’m looking into is internships and, even if they are paid, the biggest thing is you don’t get benefits.”

"On every scale this is a monumental case," said attorney Tom Goldstein.

Goldstein has a stash of quill pens - one to mark each case he's argued before the Supreme Court. The real debate here is if Congress has the authority to mandate health insurance for all Americans.

"It involves the signature accomplishment of the president and it involves a question which affects the healthcare, which is absolutely basic to a hundred million people at least," he said.

With that in mind, the justices have scheduled six hours of arguments over three days. That's the longest given any case since the 1960s. And for good reason - analysts say their decision will be cited in American courts for the next 250 years.

Carolyn Presutti is an Emmy and Silver World Medal award winning television correspondent who works out of VOA’s Washington headquarters. She has also won numerous Associated Press awards and a Clarion for her coverage of The Syrian Medical Crisis, Haiti, The Boston Marathon Bombing, Presidential Politics, The Southern Economy, and The 9/11 Bombing Anniversary. In 2013, Carolyn aired exclusive stories on the Asiana plane crash and was named VOA’s chief reporter with Google Glass.

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